Projects

The research carried out in Nutrition, Food and Health is far reaching at Imperial College, here are a few examples.

Nutrition, food and health

Impact of Food and Nutrients on colonic metabolism and gut brain signalling

Impact of Food and Nutrients on colonic metabolism and gut-brain signalling

Researcher: Claire Byrne

Supervisor: Prof. Gary Frost

Regulatory hormones are released from the gastrointestinal tract to influence a number of physiological processes, including eating behaviour. The colon contains the highest density of enteroendocrine cells, which secrete appetite suppressing hormones. These cells also express a number of receptors that have the ability to sense ingested food to reduce food intake. This gives the colon the ability to regulate appetite in response to the nutrient environment in the colon. A major component of the digesta reaching the colon is carbohydrate, which is a main fuel source of the gut microbiota. The aim of the current study is to investigate the effects of different types of carbohydrates on gut contents and the effects this has on how hungry people feel. This may be important in terms of controlling body weight and therefore preventing obesity.

Mucus lines the entire length of the gastrointestinal tract to provide lubrication for the passage of nutrients and to act as the first line of defence against pathogen invasion. Research has shown that the mucus layer becomes more permeable in disease with compromised gut barrier function and in mice fed with a low fibre, high sugar diet. There also seem to be a link between types of microbial community in the gut and the integrity of the mucus layer. Since mucus is directly linked to the host response, the understanding of how microbiota contributes to its functional properties provides insight to the mechanism in which microbiota establish communication with the host.

An innovative passive dietary monitoring sysem

An Innovative Passive Dietary Monitoring System

Researchers: Dr Benny Lo, Prof Gary Frost

Existing dietary methods are labour-intensive, expensive, and do not report nutritional intake accurately or social hierarchy of food intake. This has been a major weakness in nutritional science and a major problem for planning health policy. To enable accurate measurement of individual food and nutrient intake in low and middle-income countries, this project aims to develop a passive capturing system for dietary assessments for both adults and children living in Low or Middle-Income Countries (LMICs). The system mainly consists of wearable vision sensors, fixed cameras, and a cloud storage server. The goal of the project is to provide a low-cost and robust system for accurate measurement of individuals’ dietary intake.

Investigating the Gut-Lung axis: Colonic metabolism and lung development

PhD project (co-funded through ICL Stratigrad program)

Investigating the Gut-Lung axis. Colonic metabolism and lung development

Asthma is a chronic inflammatory disease, characterized by swelling of the airways and resulting in breathing difficulties. Of an estimated 235 million asthmatics around the world eight million patients live in the UK and only 5 million are being treated. There is no known cure for asthma and asthmatics have to rely on analgesic medication in their everyday lives. Previous studies have demonstrated that countries with diets high in meats and low in fibres have a higher prevalence of developing allergic airway diseases, in particular, asthma, as compared to Mediterranean countries where diets are rich in fibres. Fibre passes through the small intestine unaffected until it reaches the colon where it is fermented by the microbiota resulting in small molecules, such as short-chain fatty acids, which are thought to impart an anti-inflammatory effect. This project aims to investigate the effect of fibre on asthma, by the evaluation of patient data sets in conjunction with in vitro tissue culture studies.

Health outcomes in undernutrition: the role of nutrients, gut dysfunction and the gut microbiome

Undernutrition affects 462 million people worldwide with 165 million children being stunted and 52 million wasted. The UN has set a target, by 2025, to reduce the global incidence of childhood stunting by 40%.In acute malnutrition, little progress has been made in the management of severe acute malnutrition (SAM) in children, where mortality remains high. The factors underpinning SAM are complex and multifactorial, ultimately resulting in disruption of the normal gut microbiota, reduced absorption of vital nutrients, altered gut barrier function, impaired immunity and increased risk of development of infection and disease from gram-negative bacteraemia. There is an urgent need to understand how optimum gut function can be supported in the face of undernutrition and pathogens.

Our overarching strategy is to develop a programme of work to understand the relationships between undernutrition, pathogen burden, gut barrier function, the gut microbiome, and health outcomes, and to develop nutritional strategies that are context-specific to overcome nutritional challenges at key stages of child development in low and middle-income countries.

Mendelian randomization study of dietary and nutritional factors and risk of several cancers

Mendelian randomization study of dietary and nutritional factors and risk of several cancers

Researcher: Dr Kostas Tsilidis

There is ample evidence suggesting that cancer is largely a set of preventable diseases. Migrant studies in genetically identical populations have shown changes in incidence rates of the most common cancers over one or two generations, suggesting an effect of environmental factors. Among the environment, it is widely accepted that nutrition-related factors such as obesity and physical activity play an important role in the occurrence of several cancers including prostate cancer. However, the evidence for specific foods or nutrients affecting cancer risk is largely inconsistent with few exceptions. Most of the evidence regarding diet and risk of cancer occurrence emerges from observational studies, and part of the inconsistency in the observed associations might occur due to the limitations of those studies especially in the field of nutritional epidemiology. Observational studies rely often on food frequency questionnaires to measure the consumption of foods and nutrients. However, this approach is prone to measurement errors because it is based on participants’ self-reported intake that might be inaccurate leading to attenuated or inflated results. Furthermore, people who follow different dietary patterns might also differ in other aspects, which are not always captured in the list of common confounders. The aim of this project is to assess potential causality between dietary and nutritional factors and risk of several cancers (e.g. breast, colorectal, prostate) through the Mendelian Randomization (MR) approach. Results from MR studies are usually not vulnerable to biases often present in observational literature (e.g., residual environmental confounding, exposure measurement error, reverse causation bias).

Anthropometric factors and risk of oesophageal and gastric cancer by subtype

Anthropometric factors and risk of oesophageal and gastric cancer by subtype

Researcher: Dr Harinakshi SanikiniSupervisor: Dr Amanda J Cross

Body mass index (BMI) is widely used as a measure of general obesity and waist circumference and waist to hip ratio are used as measures of abdominal or central obesity. The evidence from epidemiological studies suggests that BMI is positively associated with oesophageal adenocarcinoma and gastric cardia cancer risk; while the evidence for oesophageal squamous cell carcinoma and gastric non-cardia cancer is limited. Moreover, few epidemiological studies have examined the association between abdominal obesity and risk of oesophageal and gastric cancer by subtype. The aim of this project is to prospectively examine the association between a variety of anthropometric factors and risk of oesophageal and gastric cancer by subtype.

Identifying dietary tools that prevent disordered insulin secretion from pancreatic β cells is an attractive strategy to combat the increasing prevalence of type 2 diabetes. Dietary resistant starch has been linked to improvements in the function of β cells, possibly via increased colonic fermentation and production of short chain fatty acids (SCFA). Increasing the resistant starch content of commonly consumed foods could therefore maintain glucose homeostasis at the population level. As part of Biotechnology and Biological Sciences Research Council (BBSRC) Diet and Health Research Industry Club (DRINC) initiative, variants of Pisum sativum L. (pea) are being investigated to identify the features of pea starch that make it resistant to digestion and available for colonic fermentation and SCFA production. Parallel in vitro and in vivo studies are being conducted using both whole pea seeds and pea flour to facilitate a better understanding of how cells in the pea cotyledons are affected by processing and, in turn, how this influences starch digestibility. Trials in human volunteers are being used to monitor a full spectrum of short- and long-term physiological responses relevant to pancreatic β cell function and glucose homeostasis. This project is providing new insights into variants of crops that are associated with the specific types of resistant starch that provide the best protection against defects in insulin secretion and function.

Impact of food and nutrients on colonic metabolism and gut brain signalling

Postdoctoral projects (with co-funding from BBSRC)

Impact of Food and Nutrients on colonic metabolism and gut-brain signalling

Herbs and spices have a strong cultural heritage in cooking and culinary art. Moreover, they are being used in traditional medicine based upon a broad spectrum of anecdotal medicinal. In recent years, a number of research studies have been carried out in humans and animal models to investigate the physiological benefits associated with the consumption of spices. However, little is known about their effect on the activity and composition of the gut microbiota. This project aims to investigate the effect of commonly consumed spices and herbs on the physiology of the gut, at doses that are reflective of the amounts consumed at an eating occasion. This will allow us to gain an understanding of whether the consumption of spices and herbs has an effect on the bacterial profile of the colon as well as the metabolites produced and whether this is beneficial to host health.

Intelligent food design, engineering and monitoring

Mechanical analysis and modelling the sheeting process of baked dough

A predictive tool is developed for the analysis of the industrial rolling/sheeting process of dough through the characterisation of viscoelastic behaviour of selected dough samples, and simulation of sheeting process using a combination of experimental, analytical and computational (FEA) methods.

Aeration of confectionery products via nozzle-based injection

Bubble inclusions in confectionery products impart a desirable mouth-feel and unique sensory properties. This project studies the inclusion of bubbles through a novel nozzle-based injection method. The relationship between the operational/process parameters, the flow regime upstream of the nozzle and the downstream size distribution, is studied using a model air-water mixture.

Mechanics of crushable food forms

The aim of this research was to predict and simulate the material deformation of confectionery wafers using the finite element method so as to improve the manufacturing process and increase efficiency on the assembly line. This was done experimentally, analytically and numerically at both the macroscopic and microscopic level. The findings of this research can also be used to correlate the mechanical response and sensory perception of confectionery products.

Cutting of soft solids

Cutting is an important process in the food industry, whether this on the process line or a process that occurs during consumption. The group has performed a wide range of cutting tests suitable for soft foods, including wire cutting (of cheese or gels) or blade cutting (of cheese or petfoods). The aim is to extract the intrinsic fracture toughness from such cutting data. The results are validated through alternative fracture tests such the conventional Single Edge Notch Bend tests or the Essential Work of Fracture tests. Computational models are developed to simulate the cutting process in these soft solids using cohesive zone models.

Extrusion of unleavened bread dough: experiments and simulations

An experimental and numerical study on ram extrusion of bread dough was conducted in order to develop predictive models for the pressures involved, as well as the deformation of the extruded dough. Such studies are needed as high pressures can potentially lead to significant degassing, tearing, and shearing of the dough and hence poor bread quality; the latter limits the use of extrusion processes which would otherwise be a cost-effective forming process. A laboratory extrusion rig was designed, with dies of varying angles and exit radii. A simulation of extrusion was performed to predict the extrusion pressure as well as the extrudate swell, as a function of die geometry and extrusion rate. Static zones were observed both experimentally and numerically.

Simulation of food oral processing

Simulation of food oral processing

Researchers: Maria Charalambides

The stress-strain and toughness data are used in FE models to simulate food breakdown – the viscoplastic material model is implemented. Hard foods often display low ductility and toughness while they require high bite loads. Chewy foods undergo high deformations and display high fracture toughness.

Fracture experimental methodology

Determining fracture toughness for soft, highly dissipative, solids has been a challenge for several decades. Amongst the limited experimental options for such materials is the essential work of fracture (EWF) method. However, EWF data are known to be strongly influenced by specimen size and test speed. In contrast to time-consuming imaging techniques that have been suggested to address such issues, a simple and reproducible method is proposed. The method accounts for diffuse dissipation in the specimen while ensuring consistent strain rates by scaling both the sample size and testing speed with ligament length.We compare this new method to current practice for two polymers: a starch-based food and a polyethylene (PE) tape. Our new method gives a size independent and more conservative fracture toughness. It provides key-data, essential in numerical models of the evolution of structure breakdown in soft solids as seen for example during oral processing of foods.

Enhancing consumption experience through the design of rituals

Postdoctoral projects (with co-funding from BBSRC)

Enhancing Consumption experience through the design of rituals

Researcher: Eleanor Ratcliffe

Supervisor: Dr Weston Baxter, Dr Nahalie Martin (Nestle Research)

Sometimes food innovation is less about what we eat and more about how we eat. Simple rituals such as the way we cut our meat or stir our drink can significantly enhance our consumption experience. This project seeks to understand the origin and impact of rituals in the context of food and nutrition. First, we are conducting foundational research into the structure of rituals and psychosocial mechanisms that drive them. We will then use this knowledge to design new food ritual applications and enhance the consumption experience. Though the immediate benefit of ritual design may be enhancing a user experience, we see potential for ritual design to have more widespread implications fromhealth focused behaviour change to emotional wellbeing.

Childhood obesity has grown to become one of the most dramatic features of the global obesity epidemic, with dire long-term consequences on health, social and economic outcomes. Obesity has spread to more than one in ten children aged 5-19 throughout southern Europe, in parts of central-eastern Europe and in the United Kingdom, with more than one in three children overweight in countries such as Greece, Malta and Italy. The spread of obesity has been fuelled by changes in social norms and living environments that have led to excessive and imbalanced nutrition, sedentary lifestyles, and ultimately obesity and the diseases associated with it.

STOP (Science and Technology in childhood Obesity Policy), a Horizon 2020-funded project to tackle childhood obesity, aims at expanding and consolidating the multi-disciplinary evidence base upon which effective and sustainable policies can be built to prevent and manage childhood obesity. The primary focus of STOP is on the cumulative impacts of multiple and synergistic exposures in vulnerable and socially disadvantaged children and their families, which must be a priority target for the fight against childhood obesity in Europe. STOP will identify critical stages in childhood (starting from prenatal exposures) at which interventions can be most effective and efficient.

The nutritional transition that has swept through Latin America and the Caribbean (LAC) has radically changed the face of malnourishment in LAC in only a few decades. While as recently as the 1980s, undernutrition was pervasive and persistent, today, although child and adolescent anaemia and stunting still persist, as many as one in three children are overweight. Modernization has been accompanied by dramatic changes in food consumption patterns (towards consumption of energy-rich foods), physical activities, and school and community resources. High prevalence of overweight and obesity among children and adolescents threatens to further tax health systems that are already fighting burdens of undernutrition. Behavioural factors, as well as food environments, play critical roles in the development of overweight and obesity, and these may vary in important ways by occupational status among adolescents and young adults. In this mixed-method study we aim to characterize key weight-related behaviors (e.g., consumption of sugary beverages and “junk” foods, physical activity, time spent sitting), overweight status, and dietary diversity within the context of categories of varying occupational status (e.g., student, working for wages, agricultural work, or work-student combination), time use (e.g. time spent on domestic chores and caregiving behaviors, for example), and food environments (e.g. availability, affordability and reliance on pre-packaged or pre-prepared and high-caloric foods versus healthy, nutritional alternatives) among adolescents and young adults in Peru.

Food insecurity and child and adolescent development in India

Food insecurity and child and adolescent development in India

Researcher: Dr Elisabetta Aurino

Other members of research team: Prof Marisa Miraldo (Business School), Prof Chris Millet (School of Public Health)

Food security and healthy child and adolescent development are key global challenges, as underscored by the Sustainable Development Goals. These challenges are particularly critical in India, which bears the highest burden of food insecurity globally, and where half of the country’s 1.25 billion population is below 25 years. Despite the policy relevance of these issues in India (reflected in the 2013 Food Security Act and 2014 Youth Policy), no extant research investigated the relationship between food insecurity and young people’s development in India or other developing countries. This is a critical gap as studies from advanced economies have shown that food insecure children experience many negative consequences over their life-course, which cause long-term losses in productivity, income and health, and decreased societal welfare. This project tackles this key gap by combining various sources of longitudinal data in order to assess the impact of food insecurity on multiple aspects of young people’s development such as education, psycho-social health and health risk behaviours, as well as intergenerational transmission of health.

Food security

Food insecurity and child and adolescent development in India

Food insecurity and child and adolescent development in India

Researcher: Dr Elisabetta Aurino

Other members of research team: Prof Marisa Miraldo (Business School), Prof Chris Millet (School of Public Health)

Food security and healthy child and adolescent development are key global challenges, as underscored by the Sustainable Development Goals. These challenges are particularly critical in India, which bears the highest burden of food insecurity globally, and where half of the country’s 1.25 billion population is below 25 years. Despite the policy relevance of these issues in India (reflected in the 2013 Food Security Act and 2014 Youth Policy), no extant research investigated the relationship between food insecurity and young people’s development in India or other developing countries. This is a critical gap as studies from advanced economies have shown that food insecure children experience many negative consequences over their lifecourse, which cause long-term losses in productivity, income and health, and decreased societal welfare. This project tackles this key gap by combining various sources of longitudinal data in order to assess the impact of food insecurity on multiple aspects of young people’s development such as education, psycho-social health and health risk behaviours, as well as intergenerational transmission of health.